1. Field of the Invention
The invention relates to a device for converting chemical energy of an exothermic mass into electrical energy, e.g. high temperature storage sources for dc which are intended for use in operation in wait condition and to supply on-board equipment independently for devices and equipment (heating bridges, pyro-energy sensors, micro drives, relays and the like) which are used in different systems in automated engineering, including for triggering fire extinguishing equipment, signaling devices, warning devices, jamming devices and the like).
2. Description of the Background Art
Primary stored current sources using pyrotechnic charges are known from the patent and scientific literature (Bagozki W. S., Skundin A. M., Chemische Stromquellen [Chemical Sources of Current] M. Energoizdad, 1981, pages 304-310; Crompton T., Primare Stromquellen [Primary Current Sources], N.: Mir 1986, pages 295, 328 inter alia). However, these primary stored current sources have a complicated construction and require long start-up times, since the development of the electrical current in these devices is only possible after burning off the pyrotechnic charge (pyro-heater). This guarantees the melting of the solid electrolyte (salts or salt mixtures), which is disposed between the anode and the cathode and the heating of the two electrodes to operational temperature. The activating time of the store source is reduced because the heating element is installed directly in the electrochemical element. The above mentioned construction solution of the device (Kukots F. l. inter alia Warmestromquellen, [heating current sources], Rostow-am-Don University Publishers 1989, pages 61-63) virtually excludes the construction of a battery from the current-producing parts, wherein however only those batteries are of importance (current-producing device) which comprise voltages of 9-12 V and higher.
Moreover, the presence of pyrotechnic and electrochemical components renders it necessary to produce these separately owing to fire and explosion safety regulations whilst adhering to certain regulations for the technological procedures which hampers their production. Moreover, it is also economically disadvantageous to use the. above mentioned current sources in systems for intermittent and pulsed supply.
DE-OS 2046144 describes a thermally activated galvanic primary element according to the system calcium/lithium-potassium chloride/calcium chromate comprising two outer-lying positive electrodes and an inner-lying negative electrode and a heating element, wherein the electrodes and the electrolyte layer are formed using the thin-layer method of construction and the thickness of the element perpendicular to the electrode surfaces is approximately 1.6-2.0 mm and not greater than 2.5 mm.
In so doing, the positive electrodes of the element preferably have a current collector consisting of fine mesh nickel wire into which the positive mass consisting of calcium chromate and a mixture of lithium chloride and potassium chloride is fused.
The negative electrode of the element consists preferably of a wire netting or coarse perforated sheet nickel plate onto both sides of which are pressed calcium metal layers.
The Russian application N94013374/02 (013252) describes a pyrotechnic pulsed current generator which consists of two electrodes which as a thin semi-charge consists of pyrotechnic masses with the ratio of diameter to height of 30-80. The fundamental disadvantage of this device is the short generation time (pulse not longer than 1.0 sec.) which considerably limits the application options.
The closest prior art is described in the Russian patent N2018782 in which both electrodes are designed as pressed pyrotechnic charges (semi-charges) with a ratio of diameter to height of each semi-charge equal to 2.0-2.5. In so doing, the anode as a pyrotechnic charge comprising an excess of fuel and the cathode comprising an excess of oxidation agent and the separator, which separates the anode and the cathode is formed from a porous dielectric. The cathode is produced from a mixture of lead fluoride, lithium fluoride and aluminium fluoride, the anode is produced from a mixture of lead fluoride, magnesium fluoride and lithium fluoride.
The fundamental disadvantage of this known solution is the long time period between the moment of switch-on to the moment in which the maximum current strength is achieved, which is caused by the low burning rate of the pyrotechnic electrodes and the inertia of the separator containing the pores, wherein a considerable amount of time (longer than 0.5 sec.) is required to fill the pores by means of the electrolyte in order to achieve ion permeability. Moreover, the known device is provided as a single element current source.